Well it was an electrical contractor cast it, not someone that actually does concrete work, their repairs to the parking lot where just as "impressive".
my question is how far do these bases extend below the surface of the parking lot or ground? in other words how tall is a base from the deepest point in the ground to the top part where the pole mounts?
Concrete bases are generally 5-6ft tall in total height and for parking lots some of that is above the ground. The anchor bolts for the pole are around 30-something inches tall. The base has to be below the frost line (far enough down so that the ground under the base won't freeze). The frost line in Rhode Island is 42" IIRC. It's much lower down south and higher up north. It all depends how cold it gets in the winter and soil conditions